Pagham Coastal Protection

 

We have tried to provide as much information as we can about the current situation regarding Pagham Coast Protection here. If you cannot find the answer to your question, please email coast.protection@arun.gov.uk

 

Management of the coastline

The coast around England is typically managed by either the Environment Agency (EA) or the Local Authority. At Pagham, Arun District Council manages the open coastline in front of the properties, whilst the EA maintains the defences inside the harbour. 

The EA has two main roles at Pagham. One is as the Coastal Overview body. This role requires the Environment Agency to assess projects for their viability and to distribute the funding put aside by central government for flooding and erosion projects. Another role is as a "permissive" maintainer of the inner harbour bunds. Under this role, a project is being progressed to improve the defences along the eastern part of the harbour to reduce flood risk to 88 properties at Pagham. The first phase of this work is underway and a second phase to better protect the causeway is planned.

Neither Arun District Council nor the Environment Agency has duties to protect the coast from erosion or flooding. The various Acts of Parliament under which we work bestow powers to Arun to reduce the risk of erosion and the Environment Agency to reduce the risk of flooding

Natural England is the Government's statutory adviser on the natural environment. Advice is available to regulators such as Arun DC and the EA on issues related to wildlife and designated nature conservation sites. Natural England does not make decisions on coastal or flood protection issues and are not responsible for undertaking coastal defence works. Natural England’s advice is sought when natural environment interests might be affected and this advice is taken into account when decisions are made.

 

Action taken so far

Historically, shingle was recycled from the near-shore shingle banks and placed along the Church Norton frontage, to help strengthen the southern spit. In 2003, the spit on the Church Norton side of the harbour started to accrete (grow) naturally. There was therefore no need to continue bolstering the spit and these activities were stopped. It is important to note that Pagham Harbour was not dredged

There are a number of reasons why we haven’t progressed a ‘cut the spit’ option previously, including the cost of developing, undertaking and maintaining a channel in its position prior to 2003 would be expensive (estimated at £1.5million over 5 years – and more over the full lifetime of such a scheme), there is some uncertainty that it will solve the problem in the longer term, the technical challenges associated with such a proposal and the potential increase of the flood risk from within the harbour.

Cutting a new channel through the spit is also likely to have effects on the Harbour and its habitats which would require careful assessments. Pagham Harbour is of National and International environmental importance and this would need to be taken into account through a proper assessment and therefore would need to be factored into the project cost and timeframe.  The current Central Government framework of approvals and funding has therefore led us to follow the Adaptive Management policy as set out in the Pagham to East Head Coastal Defence Strategy.

Whilst blocking the harbour mouth is technically more feasible and potentially cheaper than cutting the spit, actively closing Pagham Harbour presents a number of very challenging technical and environmental challenges. The Harbour would cease to be tidal, this presents a number of issues, including water quality and it would mean that water would permanently cover most of the mudflats. The current natural environment would entirely change, creating a new habitat as the saline conditions changed to brackish and then freshwater over time. There is also a risk that the spit may breach making it likely to reopen and therefore require further funded actions. It is therefore the belief that actively closing the harbour is not the right solution.

Many residents ask why is the revetment not working, but the simple answer is that it is working. Arun District Council, along with the Environment Agency, believes that the revetment has been key to the Pagham residents’ protection during the unrelenting severe weather of the last winter. Had the revetment not been in place, we would have lost many more metres of beach crest and probably several properties too.

The storms have accelerated the growth of the spit which, in turn, has changed the patterns of the currents in the harbour mouth. The toe of the revetment settled and the District Council undertook initial works to stabilise it and more works are planned as part of the current works.

 

The revetment

Arun District Council chose to use a rock revetment because it would “do the job” very well, was cost effective, could be installed quite quickly and would have minimal environmental impacts. A further benefit is that the rocks could be removed and re-used elsewhere if conditions at Pagham changed to the point where a revetment was no longer needed. The structure has proven effective, during last winter’s severe weather. The cost of the initial construction of the revetment was in the order of £500,000. We have had to carry out some additional works including stabilisation of some of the rock and recycling shingle. The revetment is currently providing a 20 metre wide beach in front of the properties, which is typically sufficient to absorb wave energy and reduce overtopping to a 1 in 200 year standard of protection (0.5% chance of flooding in any year). There is still some gradual erosion at the western end of the revetment; this is being addressed as part of the current remedial works.

 

Risks

There can be no guarantee that homes are 100% safe. Living close to the sea always carries some level of risk; homeowners should be aware of this and should take appropriate precautionary measures if they consider it necessary.

With the continued natural growth of the spit, the length of the channel between it and Pagham Beach has also increased. The water flowing in and out of the harbour is now tending to scour the beach between groynes 3 and 4.

During 2014 ADC has rebuilt the crest width by recycling shingle. The most recent event was at the start of October and emergency works were started, rock has recently been delivered to site to help protect this area and shingle recycling will help build a wider beach.

Across the whole coastal frontage at Pagham, there are 102 properties which could be at risk of flooding and/or erosion. At the moment, the vast majority of these properties are outside of the trigger levels mentioned above, and are not currently at risk of eroding or being flooded. Of those properties, the 15 which were most at risk (to the west) are now protected by the rock revetment. The beach in front of a few properties immediately east of the last groyne (Groyne 4) has been scoured following the partial collapse of that groyne and the growth of the spit. ADC is replacing the lost shingle and has reinforced the groyne with more rock. We are aware many people within the village are concerned about becoming at risk if the front line of properties were to erode into the sea. The land within Pagham Village is high and slopes upwards from behind Pagham Beach (after an initial dip). There is no flood route from the coast, which would put additional properties at risk. The biggest risk remains from the harbour overtopping the existing defences, placing 88 properties within the village, and the Church Farm caravan park at significant risk of flooding. The Environment Agency is leading on a partnership scheme to improve the defences on the eastern side of Pagham Harbour. Construction work on the first phase has started, phase 2 is being planned subject to funding.

Pagham is a costal location and is exposed to tidal flood and coastal erosion risks. We can reduce these risks significantly though defensive actions but cannot remove them completely. As noted above, the biggest risk remains from the harbour overtopping the existing defences and flooding up to 88 properties and Church Farm Caravan Park. However, there is an emergency plan for Pagham, this includes preparations by Arun District Council and the emergency services in case a breach does occur.

 

Monitoring

All of the beaches around our coasts are monitored, but following the adoption of the Pagham to East Head Coastal Defence Strategy in 2010, we undertook a further study recommended in the Strategy. This presented a number of ‘triggers’ which set out courses of action for various beach crest widths: 20 metres is a warning width when ADC would start monitoring the beach more frequently and begin discussing ways forward with the EA and Natural England. At 15 metres, ADC would take action, designing, gaining approval for, and putting in place, a flood risk management/erosion project. If the beach crest reduced to 10 metres, ADC would begin emergency works to rebuild the beach width.

The energy in the sea increases with storm conditions (both locally and further out to sea). A greater depth of water close to shore (tidal height) allows more of that energy to hit the shore and damage the beach. Over last winter we had high spring tides coupled with tidal surges, which led to the highest tides since 1953. The combination of tidal height and storm conditions has meant that the destructive forces acting on our coastline have been immense. As the tides drop to ‘neap’ conditions, those forces should reduce, leading to calmer conditions and the possibility of some natural recovery of the beaches. We will be keeping a close watch on all of the beaches along the coast, not just Pagham.

 

Actions being taken

For the short term ADC has received 1800 tonnes of rock which is being used to mitigate adverse effects of waves and the scour. Geotextile bags have been used with the rock and they will also be used at the west end of the revetment. As well as this, shingle re-nourishment has been started; this will continue into week (commencing 10th November)

In the longer term, as well as the previously approved £100k to address the  issues caused by last winter’s storms, Arun’s Full Council is to be asked, at its meeting on 5 November, to approve a further sum of up to £250,000; this, in part, is  intended to address the extended area of erosion, and also in part to fund further works e.g. shingle recycling before/after winter storms - for which there is currently no budget.

We have been working closely with the Pagham Flood Defence Steering Group and we recently attended a meeting in London with the Secretary of State for the Environment to try to find a long term solution to protecting properties at risk now, and in the future, on Pagham Beach. All of the available reports and other data are being forwarded to the Secretary of State’s staff and Dan Rogerson MP (the Under Secretary of State), is expected to visit Pagham shortly. The outcome of the meeting with the Secretary of State is expected in the next few weeks.

Littoral or longshore drift has carried material from the southwest along the beach to form the spit. The rate at which the spit has grown is quite surprising but it is a natural process. It must be remembered that the land upon which Pagham Beach now sits is a shingle spit which grew up after 1875. It should also be noted that just as the rate of material coming along the beach from the west has increased, it could also reduce.

If you would like to know more, please email coast.protection@arun.gov.uk